The typical American house is growing again, officials with the National Association of Home Builders say.

"The average home size has continued to rise for the past four years, from 2,362 square feet in 2009 to 2,679 square feet in 2013," said Rose Quint, NAHB assistant vice president for survey research.

Quint made the observations at the NAHB’s International Builders’ Show, which took place Feb. 4-6 in Las Vegas.

The number of homes with at least four bedrooms is also rising, from 34 percent in 2009 to 48 percent in 2013, she said.

Despite the real estate market’s collapse a few years ago, average sale prices for new homes continue to rise, going from $248,000 in 2009 to $318,000 last year.

That does price some people out of the market, Quint pointed out.

"It requires a high credit score and a nice income to qualify for a mortgage," said Quint, noting that the spread between the average Experian credit score of all U.S. consumers and the average mortgage holder’s score has risen from 33 points in the early 2000s to 58 points in 2013.

Inside these new homes, consumers are seeking high-efficiency appliances as well as green HVAC systems with programmable thermostats, officials added.